1 /* 2 * event tracer 3 * 4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com> 5 * 6 * - Added format output of fields of the trace point. 7 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>. 8 * 9 */ 10 11 #define pr_fmt(fmt) fmt 12 13 #include <linux/workqueue.h> 14 #include <linux/spinlock.h> 15 #include <linux/kthread.h> 16 #include <linux/tracefs.h> 17 #include <linux/uaccess.h> 18 #include <linux/bsearch.h> 19 #include <linux/module.h> 20 #include <linux/ctype.h> 21 #include <linux/sort.h> 22 #include <linux/slab.h> 23 #include <linux/delay.h> 24 25 #include <trace/events/sched.h> 26 27 #include <asm/setup.h> 28 29 #include "trace_output.h" 30 31 #undef TRACE_SYSTEM 32 #define TRACE_SYSTEM "TRACE_SYSTEM" 33 34 DEFINE_MUTEX(event_mutex); 35 36 LIST_HEAD(ftrace_events); 37 static LIST_HEAD(ftrace_generic_fields); 38 static LIST_HEAD(ftrace_common_fields); 39 40 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO) 41 42 static struct kmem_cache *field_cachep; 43 static struct kmem_cache *file_cachep; 44 45 static inline int system_refcount(struct event_subsystem *system) 46 { 47 return system->ref_count; 48 } 49 50 static int system_refcount_inc(struct event_subsystem *system) 51 { 52 return system->ref_count++; 53 } 54 55 static int system_refcount_dec(struct event_subsystem *system) 56 { 57 return --system->ref_count; 58 } 59 60 /* Double loops, do not use break, only goto's work */ 61 #define do_for_each_event_file(tr, file) \ 62 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \ 63 list_for_each_entry(file, &tr->events, list) 64 65 #define do_for_each_event_file_safe(tr, file) \ 66 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \ 67 struct trace_event_file *___n; \ 68 list_for_each_entry_safe(file, ___n, &tr->events, list) 69 70 #define while_for_each_event_file() \ 71 } 72 73 static struct list_head * 74 trace_get_fields(struct trace_event_call *event_call) 75 { 76 if (!event_call->class->get_fields) 77 return &event_call->class->fields; 78 return event_call->class->get_fields(event_call); 79 } 80 81 static struct ftrace_event_field * 82 __find_event_field(struct list_head *head, char *name) 83 { 84 struct ftrace_event_field *field; 85 86 list_for_each_entry(field, head, link) { 87 if (!strcmp(field->name, name)) 88 return field; 89 } 90 91 return NULL; 92 } 93 94 struct ftrace_event_field * 95 trace_find_event_field(struct trace_event_call *call, char *name) 96 { 97 struct ftrace_event_field *field; 98 struct list_head *head; 99 100 head = trace_get_fields(call); 101 field = __find_event_field(head, name); 102 if (field) 103 return field; 104 105 field = __find_event_field(&ftrace_generic_fields, name); 106 if (field) 107 return field; 108 109 return __find_event_field(&ftrace_common_fields, name); 110 } 111 112 static int __trace_define_field(struct list_head *head, const char *type, 113 const char *name, int offset, int size, 114 int is_signed, int filter_type) 115 { 116 struct ftrace_event_field *field; 117 118 field = kmem_cache_alloc(field_cachep, GFP_TRACE); 119 if (!field) 120 return -ENOMEM; 121 122 field->name = name; 123 field->type = type; 124 125 if (filter_type == FILTER_OTHER) 126 field->filter_type = filter_assign_type(type); 127 else 128 field->filter_type = filter_type; 129 130 field->offset = offset; 131 field->size = size; 132 field->is_signed = is_signed; 133 134 list_add(&field->link, head); 135 136 return 0; 137 } 138 139 int trace_define_field(struct trace_event_call *call, const char *type, 140 const char *name, int offset, int size, int is_signed, 141 int filter_type) 142 { 143 struct list_head *head; 144 145 if (WARN_ON(!call->class)) 146 return 0; 147 148 head = trace_get_fields(call); 149 return __trace_define_field(head, type, name, offset, size, 150 is_signed, filter_type); 151 } 152 EXPORT_SYMBOL_GPL(trace_define_field); 153 154 #define __generic_field(type, item, filter_type) \ 155 ret = __trace_define_field(&ftrace_generic_fields, #type, \ 156 #item, 0, 0, is_signed_type(type), \ 157 filter_type); \ 158 if (ret) \ 159 return ret; 160 161 #define __common_field(type, item) \ 162 ret = __trace_define_field(&ftrace_common_fields, #type, \ 163 "common_" #item, \ 164 offsetof(typeof(ent), item), \ 165 sizeof(ent.item), \ 166 is_signed_type(type), FILTER_OTHER); \ 167 if (ret) \ 168 return ret; 169 170 static int trace_define_generic_fields(void) 171 { 172 int ret; 173 174 __generic_field(int, CPU, FILTER_CPU); 175 __generic_field(int, cpu, FILTER_CPU); 176 __generic_field(char *, COMM, FILTER_COMM); 177 __generic_field(char *, comm, FILTER_COMM); 178 179 return ret; 180 } 181 182 static int trace_define_common_fields(void) 183 { 184 int ret; 185 struct trace_entry ent; 186 187 __common_field(unsigned short, type); 188 __common_field(unsigned char, flags); 189 __common_field(unsigned char, preempt_count); 190 __common_field(int, pid); 191 192 return ret; 193 } 194 195 static void trace_destroy_fields(struct trace_event_call *call) 196 { 197 struct ftrace_event_field *field, *next; 198 struct list_head *head; 199 200 head = trace_get_fields(call); 201 list_for_each_entry_safe(field, next, head, link) { 202 list_del(&field->link); 203 kmem_cache_free(field_cachep, field); 204 } 205 } 206 207 int trace_event_raw_init(struct trace_event_call *call) 208 { 209 int id; 210 211 id = register_trace_event(&call->event); 212 if (!id) 213 return -ENODEV; 214 215 return 0; 216 } 217 EXPORT_SYMBOL_GPL(trace_event_raw_init); 218 219 bool trace_event_ignore_this_pid(struct trace_event_file *trace_file) 220 { 221 struct trace_array *tr = trace_file->tr; 222 struct trace_array_cpu *data; 223 struct trace_pid_list *pid_list; 224 225 pid_list = rcu_dereference_sched(tr->filtered_pids); 226 if (!pid_list) 227 return false; 228 229 data = this_cpu_ptr(tr->trace_buffer.data); 230 231 return data->ignore_pid; 232 } 233 EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid); 234 235 void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer, 236 struct trace_event_file *trace_file, 237 unsigned long len) 238 { 239 struct trace_event_call *event_call = trace_file->event_call; 240 241 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) && 242 trace_event_ignore_this_pid(trace_file)) 243 return NULL; 244 245 local_save_flags(fbuffer->flags); 246 fbuffer->pc = preempt_count(); 247 fbuffer->trace_file = trace_file; 248 249 fbuffer->event = 250 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file, 251 event_call->event.type, len, 252 fbuffer->flags, fbuffer->pc); 253 if (!fbuffer->event) 254 return NULL; 255 256 fbuffer->entry = ring_buffer_event_data(fbuffer->event); 257 return fbuffer->entry; 258 } 259 EXPORT_SYMBOL_GPL(trace_event_buffer_reserve); 260 261 static DEFINE_SPINLOCK(tracepoint_iter_lock); 262 263 static void output_printk(struct trace_event_buffer *fbuffer) 264 { 265 struct trace_event_call *event_call; 266 struct trace_event *event; 267 unsigned long flags; 268 struct trace_iterator *iter = tracepoint_print_iter; 269 270 if (!iter) 271 return; 272 273 event_call = fbuffer->trace_file->event_call; 274 if (!event_call || !event_call->event.funcs || 275 !event_call->event.funcs->trace) 276 return; 277 278 event = &fbuffer->trace_file->event_call->event; 279 280 spin_lock_irqsave(&tracepoint_iter_lock, flags); 281 trace_seq_init(&iter->seq); 282 iter->ent = fbuffer->entry; 283 event_call->event.funcs->trace(iter, 0, event); 284 trace_seq_putc(&iter->seq, 0); 285 printk("%s", iter->seq.buffer); 286 287 spin_unlock_irqrestore(&tracepoint_iter_lock, flags); 288 } 289 290 void trace_event_buffer_commit(struct trace_event_buffer *fbuffer) 291 { 292 if (tracepoint_printk) 293 output_printk(fbuffer); 294 295 event_trigger_unlock_commit(fbuffer->trace_file, fbuffer->buffer, 296 fbuffer->event, fbuffer->entry, 297 fbuffer->flags, fbuffer->pc); 298 } 299 EXPORT_SYMBOL_GPL(trace_event_buffer_commit); 300 301 int trace_event_reg(struct trace_event_call *call, 302 enum trace_reg type, void *data) 303 { 304 struct trace_event_file *file = data; 305 306 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT)); 307 switch (type) { 308 case TRACE_REG_REGISTER: 309 return tracepoint_probe_register(call->tp, 310 call->class->probe, 311 file); 312 case TRACE_REG_UNREGISTER: 313 tracepoint_probe_unregister(call->tp, 314 call->class->probe, 315 file); 316 return 0; 317 318 #ifdef CONFIG_PERF_EVENTS 319 case TRACE_REG_PERF_REGISTER: 320 return tracepoint_probe_register(call->tp, 321 call->class->perf_probe, 322 call); 323 case TRACE_REG_PERF_UNREGISTER: 324 tracepoint_probe_unregister(call->tp, 325 call->class->perf_probe, 326 call); 327 return 0; 328 case TRACE_REG_PERF_OPEN: 329 case TRACE_REG_PERF_CLOSE: 330 case TRACE_REG_PERF_ADD: 331 case TRACE_REG_PERF_DEL: 332 return 0; 333 #endif 334 } 335 return 0; 336 } 337 EXPORT_SYMBOL_GPL(trace_event_reg); 338 339 void trace_event_enable_cmd_record(bool enable) 340 { 341 struct trace_event_file *file; 342 struct trace_array *tr; 343 344 mutex_lock(&event_mutex); 345 do_for_each_event_file(tr, file) { 346 347 if (!(file->flags & EVENT_FILE_FL_ENABLED)) 348 continue; 349 350 if (enable) { 351 tracing_start_cmdline_record(); 352 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags); 353 } else { 354 tracing_stop_cmdline_record(); 355 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags); 356 } 357 } while_for_each_event_file(); 358 mutex_unlock(&event_mutex); 359 } 360 361 static int __ftrace_event_enable_disable(struct trace_event_file *file, 362 int enable, int soft_disable) 363 { 364 struct trace_event_call *call = file->event_call; 365 struct trace_array *tr = file->tr; 366 int ret = 0; 367 int disable; 368 369 switch (enable) { 370 case 0: 371 /* 372 * When soft_disable is set and enable is cleared, the sm_ref 373 * reference counter is decremented. If it reaches 0, we want 374 * to clear the SOFT_DISABLED flag but leave the event in the 375 * state that it was. That is, if the event was enabled and 376 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED 377 * is set we do not want the event to be enabled before we 378 * clear the bit. 379 * 380 * When soft_disable is not set but the SOFT_MODE flag is, 381 * we do nothing. Do not disable the tracepoint, otherwise 382 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work. 383 */ 384 if (soft_disable) { 385 if (atomic_dec_return(&file->sm_ref) > 0) 386 break; 387 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED; 388 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags); 389 } else 390 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE); 391 392 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) { 393 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags); 394 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) { 395 tracing_stop_cmdline_record(); 396 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags); 397 } 398 call->class->reg(call, TRACE_REG_UNREGISTER, file); 399 } 400 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */ 401 if (file->flags & EVENT_FILE_FL_SOFT_MODE) 402 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags); 403 else 404 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags); 405 break; 406 case 1: 407 /* 408 * When soft_disable is set and enable is set, we want to 409 * register the tracepoint for the event, but leave the event 410 * as is. That means, if the event was already enabled, we do 411 * nothing (but set SOFT_MODE). If the event is disabled, we 412 * set SOFT_DISABLED before enabling the event tracepoint, so 413 * it still seems to be disabled. 414 */ 415 if (!soft_disable) 416 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags); 417 else { 418 if (atomic_inc_return(&file->sm_ref) > 1) 419 break; 420 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags); 421 } 422 423 if (!(file->flags & EVENT_FILE_FL_ENABLED)) { 424 425 /* Keep the event disabled, when going to SOFT_MODE. */ 426 if (soft_disable) 427 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags); 428 429 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) { 430 tracing_start_cmdline_record(); 431 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags); 432 } 433 ret = call->class->reg(call, TRACE_REG_REGISTER, file); 434 if (ret) { 435 tracing_stop_cmdline_record(); 436 pr_info("event trace: Could not enable event " 437 "%s\n", trace_event_name(call)); 438 break; 439 } 440 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags); 441 442 /* WAS_ENABLED gets set but never cleared. */ 443 call->flags |= TRACE_EVENT_FL_WAS_ENABLED; 444 } 445 break; 446 } 447 448 return ret; 449 } 450 451 int trace_event_enable_disable(struct trace_event_file *file, 452 int enable, int soft_disable) 453 { 454 return __ftrace_event_enable_disable(file, enable, soft_disable); 455 } 456 457 static int ftrace_event_enable_disable(struct trace_event_file *file, 458 int enable) 459 { 460 return __ftrace_event_enable_disable(file, enable, 0); 461 } 462 463 static void ftrace_clear_events(struct trace_array *tr) 464 { 465 struct trace_event_file *file; 466 467 mutex_lock(&event_mutex); 468 list_for_each_entry(file, &tr->events, list) { 469 ftrace_event_enable_disable(file, 0); 470 } 471 mutex_unlock(&event_mutex); 472 } 473 474 static int cmp_pid(const void *key, const void *elt) 475 { 476 const pid_t *search_pid = key; 477 const pid_t *pid = elt; 478 479 if (*search_pid == *pid) 480 return 0; 481 if (*search_pid < *pid) 482 return -1; 483 return 1; 484 } 485 486 static bool 487 check_ignore_pid(struct trace_pid_list *filtered_pids, struct task_struct *task) 488 { 489 pid_t search_pid; 490 pid_t *pid; 491 492 /* 493 * Return false, because if filtered_pids does not exist, 494 * all pids are good to trace. 495 */ 496 if (!filtered_pids) 497 return false; 498 499 search_pid = task->pid; 500 501 pid = bsearch(&search_pid, filtered_pids->pids, 502 filtered_pids->nr_pids, sizeof(pid_t), 503 cmp_pid); 504 if (!pid) 505 return true; 506 507 return false; 508 } 509 510 static void 511 event_filter_pid_sched_switch_probe_pre(void *data, bool preempt, 512 struct task_struct *prev, struct task_struct *next) 513 { 514 struct trace_array *tr = data; 515 struct trace_pid_list *pid_list; 516 517 pid_list = rcu_dereference_sched(tr->filtered_pids); 518 519 this_cpu_write(tr->trace_buffer.data->ignore_pid, 520 check_ignore_pid(pid_list, prev) && 521 check_ignore_pid(pid_list, next)); 522 } 523 524 static void 525 event_filter_pid_sched_switch_probe_post(void *data, bool preempt, 526 struct task_struct *prev, struct task_struct *next) 527 { 528 struct trace_array *tr = data; 529 struct trace_pid_list *pid_list; 530 531 pid_list = rcu_dereference_sched(tr->filtered_pids); 532 533 this_cpu_write(tr->trace_buffer.data->ignore_pid, 534 check_ignore_pid(pid_list, next)); 535 } 536 537 static void 538 event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task) 539 { 540 struct trace_array *tr = data; 541 struct trace_pid_list *pid_list; 542 543 /* Nothing to do if we are already tracing */ 544 if (!this_cpu_read(tr->trace_buffer.data->ignore_pid)) 545 return; 546 547 pid_list = rcu_dereference_sched(tr->filtered_pids); 548 549 this_cpu_write(tr->trace_buffer.data->ignore_pid, 550 check_ignore_pid(pid_list, task)); 551 } 552 553 static void 554 event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task) 555 { 556 struct trace_array *tr = data; 557 struct trace_pid_list *pid_list; 558 559 /* Nothing to do if we are not tracing */ 560 if (this_cpu_read(tr->trace_buffer.data->ignore_pid)) 561 return; 562 563 pid_list = rcu_dereference_sched(tr->filtered_pids); 564 565 /* Set tracing if current is enabled */ 566 this_cpu_write(tr->trace_buffer.data->ignore_pid, 567 check_ignore_pid(pid_list, current)); 568 } 569 570 static void __ftrace_clear_event_pids(struct trace_array *tr) 571 { 572 struct trace_pid_list *pid_list; 573 struct trace_event_file *file; 574 int cpu; 575 576 pid_list = rcu_dereference_protected(tr->filtered_pids, 577 lockdep_is_held(&event_mutex)); 578 if (!pid_list) 579 return; 580 581 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr); 582 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr); 583 584 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr); 585 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr); 586 587 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr); 588 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr); 589 590 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr); 591 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr); 592 593 list_for_each_entry(file, &tr->events, list) { 594 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags); 595 } 596 597 for_each_possible_cpu(cpu) 598 per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false; 599 600 rcu_assign_pointer(tr->filtered_pids, NULL); 601 602 /* Wait till all users are no longer using pid filtering */ 603 synchronize_sched(); 604 605 free_pages((unsigned long)pid_list->pids, pid_list->order); 606 kfree(pid_list); 607 } 608 609 static void ftrace_clear_event_pids(struct trace_array *tr) 610 { 611 mutex_lock(&event_mutex); 612 __ftrace_clear_event_pids(tr); 613 mutex_unlock(&event_mutex); 614 } 615 616 static void __put_system(struct event_subsystem *system) 617 { 618 struct event_filter *filter = system->filter; 619 620 WARN_ON_ONCE(system_refcount(system) == 0); 621 if (system_refcount_dec(system)) 622 return; 623 624 list_del(&system->list); 625 626 if (filter) { 627 kfree(filter->filter_string); 628 kfree(filter); 629 } 630 kfree_const(system->name); 631 kfree(system); 632 } 633 634 static void __get_system(struct event_subsystem *system) 635 { 636 WARN_ON_ONCE(system_refcount(system) == 0); 637 system_refcount_inc(system); 638 } 639 640 static void __get_system_dir(struct trace_subsystem_dir *dir) 641 { 642 WARN_ON_ONCE(dir->ref_count == 0); 643 dir->ref_count++; 644 __get_system(dir->subsystem); 645 } 646 647 static void __put_system_dir(struct trace_subsystem_dir *dir) 648 { 649 WARN_ON_ONCE(dir->ref_count == 0); 650 /* If the subsystem is about to be freed, the dir must be too */ 651 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1); 652 653 __put_system(dir->subsystem); 654 if (!--dir->ref_count) 655 kfree(dir); 656 } 657 658 static void put_system(struct trace_subsystem_dir *dir) 659 { 660 mutex_lock(&event_mutex); 661 __put_system_dir(dir); 662 mutex_unlock(&event_mutex); 663 } 664 665 static void remove_subsystem(struct trace_subsystem_dir *dir) 666 { 667 if (!dir) 668 return; 669 670 if (!--dir->nr_events) { 671 tracefs_remove_recursive(dir->entry); 672 list_del(&dir->list); 673 __put_system_dir(dir); 674 } 675 } 676 677 static void remove_event_file_dir(struct trace_event_file *file) 678 { 679 struct dentry *dir = file->dir; 680 struct dentry *child; 681 682 if (dir) { 683 spin_lock(&dir->d_lock); /* probably unneeded */ 684 list_for_each_entry(child, &dir->d_subdirs, d_child) { 685 if (d_really_is_positive(child)) /* probably unneeded */ 686 d_inode(child)->i_private = NULL; 687 } 688 spin_unlock(&dir->d_lock); 689 690 tracefs_remove_recursive(dir); 691 } 692 693 list_del(&file->list); 694 remove_subsystem(file->system); 695 free_event_filter(file->filter); 696 kmem_cache_free(file_cachep, file); 697 } 698 699 /* 700 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events. 701 */ 702 static int 703 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match, 704 const char *sub, const char *event, int set) 705 { 706 struct trace_event_file *file; 707 struct trace_event_call *call; 708 const char *name; 709 int ret = -EINVAL; 710 711 list_for_each_entry(file, &tr->events, list) { 712 713 call = file->event_call; 714 name = trace_event_name(call); 715 716 if (!name || !call->class || !call->class->reg) 717 continue; 718 719 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) 720 continue; 721 722 if (match && 723 strcmp(match, name) != 0 && 724 strcmp(match, call->class->system) != 0) 725 continue; 726 727 if (sub && strcmp(sub, call->class->system) != 0) 728 continue; 729 730 if (event && strcmp(event, name) != 0) 731 continue; 732 733 ftrace_event_enable_disable(file, set); 734 735 ret = 0; 736 } 737 738 return ret; 739 } 740 741 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match, 742 const char *sub, const char *event, int set) 743 { 744 int ret; 745 746 mutex_lock(&event_mutex); 747 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set); 748 mutex_unlock(&event_mutex); 749 750 return ret; 751 } 752 753 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set) 754 { 755 char *event = NULL, *sub = NULL, *match; 756 int ret; 757 758 /* 759 * The buf format can be <subsystem>:<event-name> 760 * *:<event-name> means any event by that name. 761 * :<event-name> is the same. 762 * 763 * <subsystem>:* means all events in that subsystem 764 * <subsystem>: means the same. 765 * 766 * <name> (no ':') means all events in a subsystem with 767 * the name <name> or any event that matches <name> 768 */ 769 770 match = strsep(&buf, ":"); 771 if (buf) { 772 sub = match; 773 event = buf; 774 match = NULL; 775 776 if (!strlen(sub) || strcmp(sub, "*") == 0) 777 sub = NULL; 778 if (!strlen(event) || strcmp(event, "*") == 0) 779 event = NULL; 780 } 781 782 ret = __ftrace_set_clr_event(tr, match, sub, event, set); 783 784 /* Put back the colon to allow this to be called again */ 785 if (buf) 786 *(buf - 1) = ':'; 787 788 return ret; 789 } 790 791 /** 792 * trace_set_clr_event - enable or disable an event 793 * @system: system name to match (NULL for any system) 794 * @event: event name to match (NULL for all events, within system) 795 * @set: 1 to enable, 0 to disable 796 * 797 * This is a way for other parts of the kernel to enable or disable 798 * event recording. 799 * 800 * Returns 0 on success, -EINVAL if the parameters do not match any 801 * registered events. 802 */ 803 int trace_set_clr_event(const char *system, const char *event, int set) 804 { 805 struct trace_array *tr = top_trace_array(); 806 807 if (!tr) 808 return -ENODEV; 809 810 return __ftrace_set_clr_event(tr, NULL, system, event, set); 811 } 812 EXPORT_SYMBOL_GPL(trace_set_clr_event); 813 814 /* 128 should be much more than enough */ 815 #define EVENT_BUF_SIZE 127 816 817 static ssize_t 818 ftrace_event_write(struct file *file, const char __user *ubuf, 819 size_t cnt, loff_t *ppos) 820 { 821 struct trace_parser parser; 822 struct seq_file *m = file->private_data; 823 struct trace_array *tr = m->private; 824 ssize_t read, ret; 825 826 if (!cnt) 827 return 0; 828 829 ret = tracing_update_buffers(); 830 if (ret < 0) 831 return ret; 832 833 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1)) 834 return -ENOMEM; 835 836 read = trace_get_user(&parser, ubuf, cnt, ppos); 837 838 if (read >= 0 && trace_parser_loaded((&parser))) { 839 int set = 1; 840 841 if (*parser.buffer == '!') 842 set = 0; 843 844 parser.buffer[parser.idx] = 0; 845 846 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set); 847 if (ret) 848 goto out_put; 849 } 850 851 ret = read; 852 853 out_put: 854 trace_parser_put(&parser); 855 856 return ret; 857 } 858 859 static void * 860 t_next(struct seq_file *m, void *v, loff_t *pos) 861 { 862 struct trace_event_file *file = v; 863 struct trace_event_call *call; 864 struct trace_array *tr = m->private; 865 866 (*pos)++; 867 868 list_for_each_entry_continue(file, &tr->events, list) { 869 call = file->event_call; 870 /* 871 * The ftrace subsystem is for showing formats only. 872 * They can not be enabled or disabled via the event files. 873 */ 874 if (call->class && call->class->reg && 875 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) 876 return file; 877 } 878 879 return NULL; 880 } 881 882 static void *t_start(struct seq_file *m, loff_t *pos) 883 { 884 struct trace_event_file *file; 885 struct trace_array *tr = m->private; 886 loff_t l; 887 888 mutex_lock(&event_mutex); 889 890 file = list_entry(&tr->events, struct trace_event_file, list); 891 for (l = 0; l <= *pos; ) { 892 file = t_next(m, file, &l); 893 if (!file) 894 break; 895 } 896 return file; 897 } 898 899 static void * 900 s_next(struct seq_file *m, void *v, loff_t *pos) 901 { 902 struct trace_event_file *file = v; 903 struct trace_array *tr = m->private; 904 905 (*pos)++; 906 907 list_for_each_entry_continue(file, &tr->events, list) { 908 if (file->flags & EVENT_FILE_FL_ENABLED) 909 return file; 910 } 911 912 return NULL; 913 } 914 915 static void *s_start(struct seq_file *m, loff_t *pos) 916 { 917 struct trace_event_file *file; 918 struct trace_array *tr = m->private; 919 loff_t l; 920 921 mutex_lock(&event_mutex); 922 923 file = list_entry(&tr->events, struct trace_event_file, list); 924 for (l = 0; l <= *pos; ) { 925 file = s_next(m, file, &l); 926 if (!file) 927 break; 928 } 929 return file; 930 } 931 932 static int t_show(struct seq_file *m, void *v) 933 { 934 struct trace_event_file *file = v; 935 struct trace_event_call *call = file->event_call; 936 937 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) 938 seq_printf(m, "%s:", call->class->system); 939 seq_printf(m, "%s\n", trace_event_name(call)); 940 941 return 0; 942 } 943 944 static void t_stop(struct seq_file *m, void *p) 945 { 946 mutex_unlock(&event_mutex); 947 } 948 949 static void *p_start(struct seq_file *m, loff_t *pos) 950 __acquires(RCU) 951 { 952 struct trace_pid_list *pid_list; 953 struct trace_array *tr = m->private; 954 955 /* 956 * Grab the mutex, to keep calls to p_next() having the same 957 * tr->filtered_pids as p_start() has. 958 * If we just passed the tr->filtered_pids around, then RCU would 959 * have been enough, but doing that makes things more complex. 960 */ 961 mutex_lock(&event_mutex); 962 rcu_read_lock_sched(); 963 964 pid_list = rcu_dereference_sched(tr->filtered_pids); 965 966 if (!pid_list || *pos >= pid_list->nr_pids) 967 return NULL; 968 969 return (void *)&pid_list->pids[*pos]; 970 } 971 972 static void p_stop(struct seq_file *m, void *p) 973 __releases(RCU) 974 { 975 rcu_read_unlock_sched(); 976 mutex_unlock(&event_mutex); 977 } 978 979 static void * 980 p_next(struct seq_file *m, void *v, loff_t *pos) 981 { 982 struct trace_array *tr = m->private; 983 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids); 984 985 (*pos)++; 986 987 if (*pos >= pid_list->nr_pids) 988 return NULL; 989 990 return (void *)&pid_list->pids[*pos]; 991 } 992 993 static int p_show(struct seq_file *m, void *v) 994 { 995 pid_t *pid = v; 996 997 seq_printf(m, "%d\n", *pid); 998 return 0; 999 } 1000 1001 static ssize_t 1002 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt, 1003 loff_t *ppos) 1004 { 1005 struct trace_event_file *file; 1006 unsigned long flags; 1007 char buf[4] = "0"; 1008 1009 mutex_lock(&event_mutex); 1010 file = event_file_data(filp); 1011 if (likely(file)) 1012 flags = file->flags; 1013 mutex_unlock(&event_mutex); 1014 1015 if (!file) 1016 return -ENODEV; 1017 1018 if (flags & EVENT_FILE_FL_ENABLED && 1019 !(flags & EVENT_FILE_FL_SOFT_DISABLED)) 1020 strcpy(buf, "1"); 1021 1022 if (flags & EVENT_FILE_FL_SOFT_DISABLED || 1023 flags & EVENT_FILE_FL_SOFT_MODE) 1024 strcat(buf, "*"); 1025 1026 strcat(buf, "\n"); 1027 1028 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf)); 1029 } 1030 1031 static ssize_t 1032 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, 1033 loff_t *ppos) 1034 { 1035 struct trace_event_file *file; 1036 unsigned long val; 1037 int ret; 1038 1039 ret = kstrtoul_from_user(ubuf, cnt, 10, &val); 1040 if (ret) 1041 return ret; 1042 1043 ret = tracing_update_buffers(); 1044 if (ret < 0) 1045 return ret; 1046 1047 switch (val) { 1048 case 0: 1049 case 1: 1050 ret = -ENODEV; 1051 mutex_lock(&event_mutex); 1052 file = event_file_data(filp); 1053 if (likely(file)) 1054 ret = ftrace_event_enable_disable(file, val); 1055 mutex_unlock(&event_mutex); 1056 break; 1057 1058 default: 1059 return -EINVAL; 1060 } 1061 1062 *ppos += cnt; 1063 1064 return ret ? ret : cnt; 1065 } 1066 1067 static ssize_t 1068 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt, 1069 loff_t *ppos) 1070 { 1071 const char set_to_char[4] = { '?', '0', '1', 'X' }; 1072 struct trace_subsystem_dir *dir = filp->private_data; 1073 struct event_subsystem *system = dir->subsystem; 1074 struct trace_event_call *call; 1075 struct trace_event_file *file; 1076 struct trace_array *tr = dir->tr; 1077 char buf[2]; 1078 int set = 0; 1079 int ret; 1080 1081 mutex_lock(&event_mutex); 1082 list_for_each_entry(file, &tr->events, list) { 1083 call = file->event_call; 1084 if (!trace_event_name(call) || !call->class || !call->class->reg) 1085 continue; 1086 1087 if (system && strcmp(call->class->system, system->name) != 0) 1088 continue; 1089 1090 /* 1091 * We need to find out if all the events are set 1092 * or if all events or cleared, or if we have 1093 * a mixture. 1094 */ 1095 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED)); 1096 1097 /* 1098 * If we have a mixture, no need to look further. 1099 */ 1100 if (set == 3) 1101 break; 1102 } 1103 mutex_unlock(&event_mutex); 1104 1105 buf[0] = set_to_char[set]; 1106 buf[1] = '\n'; 1107 1108 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); 1109 1110 return ret; 1111 } 1112 1113 static ssize_t 1114 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, 1115 loff_t *ppos) 1116 { 1117 struct trace_subsystem_dir *dir = filp->private_data; 1118 struct event_subsystem *system = dir->subsystem; 1119 const char *name = NULL; 1120 unsigned long val; 1121 ssize_t ret; 1122 1123 ret = kstrtoul_from_user(ubuf, cnt, 10, &val); 1124 if (ret) 1125 return ret; 1126 1127 ret = tracing_update_buffers(); 1128 if (ret < 0) 1129 return ret; 1130 1131 if (val != 0 && val != 1) 1132 return -EINVAL; 1133 1134 /* 1135 * Opening of "enable" adds a ref count to system, 1136 * so the name is safe to use. 1137 */ 1138 if (system) 1139 name = system->name; 1140 1141 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val); 1142 if (ret) 1143 goto out; 1144 1145 ret = cnt; 1146 1147 out: 1148 *ppos += cnt; 1149 1150 return ret; 1151 } 1152 1153 enum { 1154 FORMAT_HEADER = 1, 1155 FORMAT_FIELD_SEPERATOR = 2, 1156 FORMAT_PRINTFMT = 3, 1157 }; 1158 1159 static void *f_next(struct seq_file *m, void *v, loff_t *pos) 1160 { 1161 struct trace_event_call *call = event_file_data(m->private); 1162 struct list_head *common_head = &ftrace_common_fields; 1163 struct list_head *head = trace_get_fields(call); 1164 struct list_head *node = v; 1165 1166 (*pos)++; 1167 1168 switch ((unsigned long)v) { 1169 case FORMAT_HEADER: 1170 node = common_head; 1171 break; 1172 1173 case FORMAT_FIELD_SEPERATOR: 1174 node = head; 1175 break; 1176 1177 case FORMAT_PRINTFMT: 1178 /* all done */ 1179 return NULL; 1180 } 1181 1182 node = node->prev; 1183 if (node == common_head) 1184 return (void *)FORMAT_FIELD_SEPERATOR; 1185 else if (node == head) 1186 return (void *)FORMAT_PRINTFMT; 1187 else 1188 return node; 1189 } 1190 1191 static int f_show(struct seq_file *m, void *v) 1192 { 1193 struct trace_event_call *call = event_file_data(m->private); 1194 struct ftrace_event_field *field; 1195 const char *array_descriptor; 1196 1197 switch ((unsigned long)v) { 1198 case FORMAT_HEADER: 1199 seq_printf(m, "name: %s\n", trace_event_name(call)); 1200 seq_printf(m, "ID: %d\n", call->event.type); 1201 seq_puts(m, "format:\n"); 1202 return 0; 1203 1204 case FORMAT_FIELD_SEPERATOR: 1205 seq_putc(m, '\n'); 1206 return 0; 1207 1208 case FORMAT_PRINTFMT: 1209 seq_printf(m, "\nprint fmt: %s\n", 1210 call->print_fmt); 1211 return 0; 1212 } 1213 1214 field = list_entry(v, struct ftrace_event_field, link); 1215 /* 1216 * Smartly shows the array type(except dynamic array). 1217 * Normal: 1218 * field:TYPE VAR 1219 * If TYPE := TYPE[LEN], it is shown: 1220 * field:TYPE VAR[LEN] 1221 */ 1222 array_descriptor = strchr(field->type, '['); 1223 1224 if (!strncmp(field->type, "__data_loc", 10)) 1225 array_descriptor = NULL; 1226 1227 if (!array_descriptor) 1228 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n", 1229 field->type, field->name, field->offset, 1230 field->size, !!field->is_signed); 1231 else 1232 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n", 1233 (int)(array_descriptor - field->type), 1234 field->type, field->name, 1235 array_descriptor, field->offset, 1236 field->size, !!field->is_signed); 1237 1238 return 0; 1239 } 1240 1241 static void *f_start(struct seq_file *m, loff_t *pos) 1242 { 1243 void *p = (void *)FORMAT_HEADER; 1244 loff_t l = 0; 1245 1246 /* ->stop() is called even if ->start() fails */ 1247 mutex_lock(&event_mutex); 1248 if (!event_file_data(m->private)) 1249 return ERR_PTR(-ENODEV); 1250 1251 while (l < *pos && p) 1252 p = f_next(m, p, &l); 1253 1254 return p; 1255 } 1256 1257 static void f_stop(struct seq_file *m, void *p) 1258 { 1259 mutex_unlock(&event_mutex); 1260 } 1261 1262 static const struct seq_operations trace_format_seq_ops = { 1263 .start = f_start, 1264 .next = f_next, 1265 .stop = f_stop, 1266 .show = f_show, 1267 }; 1268 1269 static int trace_format_open(struct inode *inode, struct file *file) 1270 { 1271 struct seq_file *m; 1272 int ret; 1273 1274 ret = seq_open(file, &trace_format_seq_ops); 1275 if (ret < 0) 1276 return ret; 1277 1278 m = file->private_data; 1279 m->private = file; 1280 1281 return 0; 1282 } 1283 1284 static ssize_t 1285 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) 1286 { 1287 int id = (long)event_file_data(filp); 1288 char buf[32]; 1289 int len; 1290 1291 if (*ppos) 1292 return 0; 1293 1294 if (unlikely(!id)) 1295 return -ENODEV; 1296 1297 len = sprintf(buf, "%d\n", id); 1298 1299 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len); 1300 } 1301 1302 static ssize_t 1303 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt, 1304 loff_t *ppos) 1305 { 1306 struct trace_event_file *file; 1307 struct trace_seq *s; 1308 int r = -ENODEV; 1309 1310 if (*ppos) 1311 return 0; 1312 1313 s = kmalloc(sizeof(*s), GFP_KERNEL); 1314 1315 if (!s) 1316 return -ENOMEM; 1317 1318 trace_seq_init(s); 1319 1320 mutex_lock(&event_mutex); 1321 file = event_file_data(filp); 1322 if (file) 1323 print_event_filter(file, s); 1324 mutex_unlock(&event_mutex); 1325 1326 if (file) 1327 r = simple_read_from_buffer(ubuf, cnt, ppos, 1328 s->buffer, trace_seq_used(s)); 1329 1330 kfree(s); 1331 1332 return r; 1333 } 1334 1335 static ssize_t 1336 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, 1337 loff_t *ppos) 1338 { 1339 struct trace_event_file *file; 1340 char *buf; 1341 int err = -ENODEV; 1342 1343 if (cnt >= PAGE_SIZE) 1344 return -EINVAL; 1345 1346 buf = memdup_user_nul(ubuf, cnt); 1347 if (IS_ERR(buf)) 1348 return PTR_ERR(buf); 1349 1350 mutex_lock(&event_mutex); 1351 file = event_file_data(filp); 1352 if (file) 1353 err = apply_event_filter(file, buf); 1354 mutex_unlock(&event_mutex); 1355 1356 kfree(buf); 1357 if (err < 0) 1358 return err; 1359 1360 *ppos += cnt; 1361 1362 return cnt; 1363 } 1364 1365 static LIST_HEAD(event_subsystems); 1366 1367 static int subsystem_open(struct inode *inode, struct file *filp) 1368 { 1369 struct event_subsystem *system = NULL; 1370 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */ 1371 struct trace_array *tr; 1372 int ret; 1373 1374 if (tracing_is_disabled()) 1375 return -ENODEV; 1376 1377 /* Make sure the system still exists */ 1378 mutex_lock(&trace_types_lock); 1379 mutex_lock(&event_mutex); 1380 list_for_each_entry(tr, &ftrace_trace_arrays, list) { 1381 list_for_each_entry(dir, &tr->systems, list) { 1382 if (dir == inode->i_private) { 1383 /* Don't open systems with no events */ 1384 if (dir->nr_events) { 1385 __get_system_dir(dir); 1386 system = dir->subsystem; 1387 } 1388 goto exit_loop; 1389 } 1390 } 1391 } 1392 exit_loop: 1393 mutex_unlock(&event_mutex); 1394 mutex_unlock(&trace_types_lock); 1395 1396 if (!system) 1397 return -ENODEV; 1398 1399 /* Some versions of gcc think dir can be uninitialized here */ 1400 WARN_ON(!dir); 1401 1402 /* Still need to increment the ref count of the system */ 1403 if (trace_array_get(tr) < 0) { 1404 put_system(dir); 1405 return -ENODEV; 1406 } 1407 1408 ret = tracing_open_generic(inode, filp); 1409 if (ret < 0) { 1410 trace_array_put(tr); 1411 put_system(dir); 1412 } 1413 1414 return ret; 1415 } 1416 1417 static int system_tr_open(struct inode *inode, struct file *filp) 1418 { 1419 struct trace_subsystem_dir *dir; 1420 struct trace_array *tr = inode->i_private; 1421 int ret; 1422 1423 if (tracing_is_disabled()) 1424 return -ENODEV; 1425 1426 if (trace_array_get(tr) < 0) 1427 return -ENODEV; 1428 1429 /* Make a temporary dir that has no system but points to tr */ 1430 dir = kzalloc(sizeof(*dir), GFP_KERNEL); 1431 if (!dir) { 1432 trace_array_put(tr); 1433 return -ENOMEM; 1434 } 1435 1436 dir->tr = tr; 1437 1438 ret = tracing_open_generic(inode, filp); 1439 if (ret < 0) { 1440 trace_array_put(tr); 1441 kfree(dir); 1442 return ret; 1443 } 1444 1445 filp->private_data = dir; 1446 1447 return 0; 1448 } 1449 1450 static int subsystem_release(struct inode *inode, struct file *file) 1451 { 1452 struct trace_subsystem_dir *dir = file->private_data; 1453 1454 trace_array_put(dir->tr); 1455 1456 /* 1457 * If dir->subsystem is NULL, then this is a temporary 1458 * descriptor that was made for a trace_array to enable 1459 * all subsystems. 1460 */ 1461 if (dir->subsystem) 1462 put_system(dir); 1463 else 1464 kfree(dir); 1465 1466 return 0; 1467 } 1468 1469 static ssize_t 1470 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt, 1471 loff_t *ppos) 1472 { 1473 struct trace_subsystem_dir *dir = filp->private_data; 1474 struct event_subsystem *system = dir->subsystem; 1475 struct trace_seq *s; 1476 int r; 1477 1478 if (*ppos) 1479 return 0; 1480 1481 s = kmalloc(sizeof(*s), GFP_KERNEL); 1482 if (!s) 1483 return -ENOMEM; 1484 1485 trace_seq_init(s); 1486 1487 print_subsystem_event_filter(system, s); 1488 r = simple_read_from_buffer(ubuf, cnt, ppos, 1489 s->buffer, trace_seq_used(s)); 1490 1491 kfree(s); 1492 1493 return r; 1494 } 1495 1496 static ssize_t 1497 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, 1498 loff_t *ppos) 1499 { 1500 struct trace_subsystem_dir *dir = filp->private_data; 1501 char *buf; 1502 int err; 1503 1504 if (cnt >= PAGE_SIZE) 1505 return -EINVAL; 1506 1507 buf = memdup_user_nul(ubuf, cnt); 1508 if (IS_ERR(buf)) 1509 return PTR_ERR(buf); 1510 1511 err = apply_subsystem_event_filter(dir, buf); 1512 kfree(buf); 1513 if (err < 0) 1514 return err; 1515 1516 *ppos += cnt; 1517 1518 return cnt; 1519 } 1520 1521 static ssize_t 1522 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) 1523 { 1524 int (*func)(struct trace_seq *s) = filp->private_data; 1525 struct trace_seq *s; 1526 int r; 1527 1528 if (*ppos) 1529 return 0; 1530 1531 s = kmalloc(sizeof(*s), GFP_KERNEL); 1532 if (!s) 1533 return -ENOMEM; 1534 1535 trace_seq_init(s); 1536 1537 func(s); 1538 r = simple_read_from_buffer(ubuf, cnt, ppos, 1539 s->buffer, trace_seq_used(s)); 1540 1541 kfree(s); 1542 1543 return r; 1544 } 1545 1546 static int max_pids(struct trace_pid_list *pid_list) 1547 { 1548 return (PAGE_SIZE << pid_list->order) / sizeof(pid_t); 1549 } 1550 1551 static void ignore_task_cpu(void *data) 1552 { 1553 struct trace_array *tr = data; 1554 struct trace_pid_list *pid_list; 1555 1556 /* 1557 * This function is called by on_each_cpu() while the 1558 * event_mutex is held. 1559 */ 1560 pid_list = rcu_dereference_protected(tr->filtered_pids, 1561 mutex_is_locked(&event_mutex)); 1562 1563 this_cpu_write(tr->trace_buffer.data->ignore_pid, 1564 check_ignore_pid(pid_list, current)); 1565 } 1566 1567 static ssize_t 1568 ftrace_event_pid_write(struct file *filp, const char __user *ubuf, 1569 size_t cnt, loff_t *ppos) 1570 { 1571 struct seq_file *m = filp->private_data; 1572 struct trace_array *tr = m->private; 1573 struct trace_pid_list *filtered_pids = NULL; 1574 struct trace_pid_list *pid_list = NULL; 1575 struct trace_event_file *file; 1576 struct trace_parser parser; 1577 unsigned long val; 1578 loff_t this_pos; 1579 ssize_t read = 0; 1580 ssize_t ret = 0; 1581 pid_t pid; 1582 int i; 1583 1584 if (!cnt) 1585 return 0; 1586 1587 ret = tracing_update_buffers(); 1588 if (ret < 0) 1589 return ret; 1590 1591 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1)) 1592 return -ENOMEM; 1593 1594 mutex_lock(&event_mutex); 1595 /* 1596 * Load as many pids into the array before doing a 1597 * swap from the tr->filtered_pids to the new list. 1598 */ 1599 while (cnt > 0) { 1600 1601 this_pos = 0; 1602 1603 ret = trace_get_user(&parser, ubuf, cnt, &this_pos); 1604 if (ret < 0 || !trace_parser_loaded(&parser)) 1605 break; 1606 1607 read += ret; 1608 ubuf += ret; 1609 cnt -= ret; 1610 1611 parser.buffer[parser.idx] = 0; 1612 1613 ret = -EINVAL; 1614 if (kstrtoul(parser.buffer, 0, &val)) 1615 break; 1616 if (val > INT_MAX) 1617 break; 1618 1619 pid = (pid_t)val; 1620 1621 ret = -ENOMEM; 1622 if (!pid_list) { 1623 pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL); 1624 if (!pid_list) 1625 break; 1626 1627 filtered_pids = rcu_dereference_protected(tr->filtered_pids, 1628 lockdep_is_held(&event_mutex)); 1629 if (filtered_pids) 1630 pid_list->order = filtered_pids->order; 1631 else 1632 pid_list->order = 0; 1633 1634 pid_list->pids = (void *)__get_free_pages(GFP_KERNEL, 1635 pid_list->order); 1636 if (!pid_list->pids) 1637 break; 1638 1639 if (filtered_pids) { 1640 pid_list->nr_pids = filtered_pids->nr_pids; 1641 memcpy(pid_list->pids, filtered_pids->pids, 1642 pid_list->nr_pids * sizeof(pid_t)); 1643 } else 1644 pid_list->nr_pids = 0; 1645 } 1646 1647 if (pid_list->nr_pids >= max_pids(pid_list)) { 1648 pid_t *pid_page; 1649 1650 pid_page = (void *)__get_free_pages(GFP_KERNEL, 1651 pid_list->order + 1); 1652 if (!pid_page) 1653 break; 1654 memcpy(pid_page, pid_list->pids, 1655 pid_list->nr_pids * sizeof(pid_t)); 1656 free_pages((unsigned long)pid_list->pids, pid_list->order); 1657 1658 pid_list->order++; 1659 pid_list->pids = pid_page; 1660 } 1661 1662 pid_list->pids[pid_list->nr_pids++] = pid; 1663 trace_parser_clear(&parser); 1664 ret = 0; 1665 } 1666 trace_parser_put(&parser); 1667 1668 if (ret < 0) { 1669 if (pid_list) 1670 free_pages((unsigned long)pid_list->pids, pid_list->order); 1671 kfree(pid_list); 1672 mutex_unlock(&event_mutex); 1673 return ret; 1674 } 1675 1676 if (!pid_list) { 1677 mutex_unlock(&event_mutex); 1678 return ret; 1679 } 1680 1681 sort(pid_list->pids, pid_list->nr_pids, sizeof(pid_t), cmp_pid, NULL); 1682 1683 /* Remove duplicates */ 1684 for (i = 1; i < pid_list->nr_pids; i++) { 1685 int start = i; 1686 1687 while (i < pid_list->nr_pids && 1688 pid_list->pids[i - 1] == pid_list->pids[i]) 1689 i++; 1690 1691 if (start != i) { 1692 if (i < pid_list->nr_pids) { 1693 memmove(&pid_list->pids[start], &pid_list->pids[i], 1694 (pid_list->nr_pids - i) * sizeof(pid_t)); 1695 pid_list->nr_pids -= i - start; 1696 i = start; 1697 } else 1698 pid_list->nr_pids = start; 1699 } 1700 } 1701 1702 rcu_assign_pointer(tr->filtered_pids, pid_list); 1703 1704 list_for_each_entry(file, &tr->events, list) { 1705 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags); 1706 } 1707 1708 if (filtered_pids) { 1709 synchronize_sched(); 1710 1711 free_pages((unsigned long)filtered_pids->pids, filtered_pids->order); 1712 kfree(filtered_pids); 1713 } else { 1714 /* 1715 * Register a probe that is called before all other probes 1716 * to set ignore_pid if next or prev do not match. 1717 * Register a probe this is called after all other probes 1718 * to only keep ignore_pid set if next pid matches. 1719 */ 1720 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre, 1721 tr, INT_MAX); 1722 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post, 1723 tr, 0); 1724 1725 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, 1726 tr, INT_MAX); 1727 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, 1728 tr, 0); 1729 1730 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, 1731 tr, INT_MAX); 1732 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, 1733 tr, 0); 1734 1735 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre, 1736 tr, INT_MAX); 1737 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post, 1738 tr, 0); 1739 } 1740 1741 /* 1742 * Ignoring of pids is done at task switch. But we have to 1743 * check for those tasks that are currently running. 1744 * Always do this in case a pid was appended or removed. 1745 */ 1746 on_each_cpu(ignore_task_cpu, tr, 1); 1747 1748 mutex_unlock(&event_mutex); 1749 1750 ret = read; 1751 *ppos += read; 1752 1753 return ret; 1754 } 1755 1756 static int ftrace_event_avail_open(struct inode *inode, struct file *file); 1757 static int ftrace_event_set_open(struct inode *inode, struct file *file); 1758 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file); 1759 static int ftrace_event_release(struct inode *inode, struct file *file); 1760 1761 static const struct seq_operations show_event_seq_ops = { 1762 .start = t_start, 1763 .next = t_next, 1764 .show = t_show, 1765 .stop = t_stop, 1766 }; 1767 1768 static const struct seq_operations show_set_event_seq_ops = { 1769 .start = s_start, 1770 .next = s_next, 1771 .show = t_show, 1772 .stop = t_stop, 1773 }; 1774 1775 static const struct seq_operations show_set_pid_seq_ops = { 1776 .start = p_start, 1777 .next = p_next, 1778 .show = p_show, 1779 .stop = p_stop, 1780 }; 1781 1782 static const struct file_operations ftrace_avail_fops = { 1783 .open = ftrace_event_avail_open, 1784 .read = seq_read, 1785 .llseek = seq_lseek, 1786 .release = seq_release, 1787 }; 1788 1789 static const struct file_operations ftrace_set_event_fops = { 1790 .open = ftrace_event_set_open, 1791 .read = seq_read, 1792 .write = ftrace_event_write, 1793 .llseek = seq_lseek, 1794 .release = ftrace_event_release, 1795 }; 1796 1797 static const struct file_operations ftrace_set_event_pid_fops = { 1798 .open = ftrace_event_set_pid_open, 1799 .read = seq_read, 1800 .write = ftrace_event_pid_write, 1801 .llseek = seq_lseek, 1802 .release = ftrace_event_release, 1803 }; 1804 1805 static const struct file_operations ftrace_enable_fops = { 1806 .open = tracing_open_generic, 1807 .read = event_enable_read, 1808 .write = event_enable_write, 1809 .llseek = default_llseek, 1810 }; 1811 1812 static const struct file_operations ftrace_event_format_fops = { 1813 .open = trace_format_open, 1814 .read = seq_read, 1815 .llseek = seq_lseek, 1816 .release = seq_release, 1817 }; 1818 1819 static const struct file_operations ftrace_event_id_fops = { 1820 .read = event_id_read, 1821 .llseek = default_llseek, 1822 }; 1823 1824 static const struct file_operations ftrace_event_filter_fops = { 1825 .open = tracing_open_generic, 1826 .read = event_filter_read, 1827 .write = event_filter_write, 1828 .llseek = default_llseek, 1829 }; 1830 1831 static const struct file_operations ftrace_subsystem_filter_fops = { 1832 .open = subsystem_open, 1833 .read = subsystem_filter_read, 1834 .write = subsystem_filter_write, 1835 .llseek = default_llseek, 1836 .release = subsystem_release, 1837 }; 1838 1839 static const struct file_operations ftrace_system_enable_fops = { 1840 .open = subsystem_open, 1841 .read = system_enable_read, 1842 .write = system_enable_write, 1843 .llseek = default_llseek, 1844 .release = subsystem_release, 1845 }; 1846 1847 static const struct file_operations ftrace_tr_enable_fops = { 1848 .open = system_tr_open, 1849 .read = system_enable_read, 1850 .write = system_enable_write, 1851 .llseek = default_llseek, 1852 .release = subsystem_release, 1853 }; 1854 1855 static const struct file_operations ftrace_show_header_fops = { 1856 .open = tracing_open_generic, 1857 .read = show_header, 1858 .llseek = default_llseek, 1859 }; 1860 1861 static int 1862 ftrace_event_open(struct inode *inode, struct file *file, 1863 const struct seq_operations *seq_ops) 1864 { 1865 struct seq_file *m; 1866 int ret; 1867 1868 ret = seq_open(file, seq_ops); 1869 if (ret < 0) 1870 return ret; 1871 m = file->private_data; 1872 /* copy tr over to seq ops */ 1873 m->private = inode->i_private; 1874 1875 return ret; 1876 } 1877 1878 static int ftrace_event_release(struct inode *inode, struct file *file) 1879 { 1880 struct trace_array *tr = inode->i_private; 1881 1882 trace_array_put(tr); 1883 1884 return seq_release(inode, file); 1885 } 1886 1887 static int 1888 ftrace_event_avail_open(struct inode *inode, struct file *file) 1889 { 1890 const struct seq_operations *seq_ops = &show_event_seq_ops; 1891 1892 return ftrace_event_open(inode, file, seq_ops); 1893 } 1894 1895 static int 1896 ftrace_event_set_open(struct inode *inode, struct file *file) 1897 { 1898 const struct seq_operations *seq_ops = &show_set_event_seq_ops; 1899 struct trace_array *tr = inode->i_private; 1900 int ret; 1901 1902 if (trace_array_get(tr) < 0) 1903 return -ENODEV; 1904 1905 if ((file->f_mode & FMODE_WRITE) && 1906 (file->f_flags & O_TRUNC)) 1907 ftrace_clear_events(tr); 1908 1909 ret = ftrace_event_open(inode, file, seq_ops); 1910 if (ret < 0) 1911 trace_array_put(tr); 1912 return ret; 1913 } 1914 1915 static int 1916 ftrace_event_set_pid_open(struct inode *inode, struct file *file) 1917 { 1918 const struct seq_operations *seq_ops = &show_set_pid_seq_ops; 1919 struct trace_array *tr = inode->i_private; 1920 int ret; 1921 1922 if (trace_array_get(tr) < 0) 1923 return -ENODEV; 1924 1925 if ((file->f_mode & FMODE_WRITE) && 1926 (file->f_flags & O_TRUNC)) 1927 ftrace_clear_event_pids(tr); 1928 1929 ret = ftrace_event_open(inode, file, seq_ops); 1930 if (ret < 0) 1931 trace_array_put(tr); 1932 return ret; 1933 } 1934 1935 static struct event_subsystem * 1936 create_new_subsystem(const char *name) 1937 { 1938 struct event_subsystem *system; 1939 1940 /* need to create new entry */ 1941 system = kmalloc(sizeof(*system), GFP_KERNEL); 1942 if (!system) 1943 return NULL; 1944 1945 system->ref_count = 1; 1946 1947 /* Only allocate if dynamic (kprobes and modules) */ 1948 system->name = kstrdup_const(name, GFP_KERNEL); 1949 if (!system->name) 1950 goto out_free; 1951 1952 system->filter = NULL; 1953 1954 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL); 1955 if (!system->filter) 1956 goto out_free; 1957 1958 list_add(&system->list, &event_subsystems); 1959 1960 return system; 1961 1962 out_free: 1963 kfree_const(system->name); 1964 kfree(system); 1965 return NULL; 1966 } 1967 1968 static struct dentry * 1969 event_subsystem_dir(struct trace_array *tr, const char *name, 1970 struct trace_event_file *file, struct dentry *parent) 1971 { 1972 struct trace_subsystem_dir *dir; 1973 struct event_subsystem *system; 1974 struct dentry *entry; 1975 1976 /* First see if we did not already create this dir */ 1977 list_for_each_entry(dir, &tr->systems, list) { 1978 system = dir->subsystem; 1979 if (strcmp(system->name, name) == 0) { 1980 dir->nr_events++; 1981 file->system = dir; 1982 return dir->entry; 1983 } 1984 } 1985 1986 /* Now see if the system itself exists. */ 1987 list_for_each_entry(system, &event_subsystems, list) { 1988 if (strcmp(system->name, name) == 0) 1989 break; 1990 } 1991 /* Reset system variable when not found */ 1992 if (&system->list == &event_subsystems) 1993 system = NULL; 1994 1995 dir = kmalloc(sizeof(*dir), GFP_KERNEL); 1996 if (!dir) 1997 goto out_fail; 1998 1999 if (!system) { 2000 system = create_new_subsystem(name); 2001 if (!system) 2002 goto out_free; 2003 } else 2004 __get_system(system); 2005 2006 dir->entry = tracefs_create_dir(name, parent); 2007 if (!dir->entry) { 2008 pr_warn("Failed to create system directory %s\n", name); 2009 __put_system(system); 2010 goto out_free; 2011 } 2012 2013 dir->tr = tr; 2014 dir->ref_count = 1; 2015 dir->nr_events = 1; 2016 dir->subsystem = system; 2017 file->system = dir; 2018 2019 entry = tracefs_create_file("filter", 0644, dir->entry, dir, 2020 &ftrace_subsystem_filter_fops); 2021 if (!entry) { 2022 kfree(system->filter); 2023 system->filter = NULL; 2024 pr_warn("Could not create tracefs '%s/filter' entry\n", name); 2025 } 2026 2027 trace_create_file("enable", 0644, dir->entry, dir, 2028 &ftrace_system_enable_fops); 2029 2030 list_add(&dir->list, &tr->systems); 2031 2032 return dir->entry; 2033 2034 out_free: 2035 kfree(dir); 2036 out_fail: 2037 /* Only print this message if failed on memory allocation */ 2038 if (!dir || !system) 2039 pr_warn("No memory to create event subsystem %s\n", name); 2040 return NULL; 2041 } 2042 2043 static int 2044 event_create_dir(struct dentry *parent, struct trace_event_file *file) 2045 { 2046 struct trace_event_call *call = file->event_call; 2047 struct trace_array *tr = file->tr; 2048 struct list_head *head; 2049 struct dentry *d_events; 2050 const char *name; 2051 int ret; 2052 2053 /* 2054 * If the trace point header did not define TRACE_SYSTEM 2055 * then the system would be called "TRACE_SYSTEM". 2056 */ 2057 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) { 2058 d_events = event_subsystem_dir(tr, call->class->system, file, parent); 2059 if (!d_events) 2060 return -ENOMEM; 2061 } else 2062 d_events = parent; 2063 2064 name = trace_event_name(call); 2065 file->dir = tracefs_create_dir(name, d_events); 2066 if (!file->dir) { 2067 pr_warn("Could not create tracefs '%s' directory\n", name); 2068 return -1; 2069 } 2070 2071 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) 2072 trace_create_file("enable", 0644, file->dir, file, 2073 &ftrace_enable_fops); 2074 2075 #ifdef CONFIG_PERF_EVENTS 2076 if (call->event.type && call->class->reg) 2077 trace_create_file("id", 0444, file->dir, 2078 (void *)(long)call->event.type, 2079 &ftrace_event_id_fops); 2080 #endif 2081 2082 /* 2083 * Other events may have the same class. Only update 2084 * the fields if they are not already defined. 2085 */ 2086 head = trace_get_fields(call); 2087 if (list_empty(head)) { 2088 ret = call->class->define_fields(call); 2089 if (ret < 0) { 2090 pr_warn("Could not initialize trace point events/%s\n", 2091 name); 2092 return -1; 2093 } 2094 } 2095 trace_create_file("filter", 0644, file->dir, file, 2096 &ftrace_event_filter_fops); 2097 2098 /* 2099 * Only event directories that can be enabled should have 2100 * triggers. 2101 */ 2102 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) 2103 trace_create_file("trigger", 0644, file->dir, file, 2104 &event_trigger_fops); 2105 2106 trace_create_file("format", 0444, file->dir, call, 2107 &ftrace_event_format_fops); 2108 2109 return 0; 2110 } 2111 2112 static void remove_event_from_tracers(struct trace_event_call *call) 2113 { 2114 struct trace_event_file *file; 2115 struct trace_array *tr; 2116 2117 do_for_each_event_file_safe(tr, file) { 2118 if (file->event_call != call) 2119 continue; 2120 2121 remove_event_file_dir(file); 2122 /* 2123 * The do_for_each_event_file_safe() is 2124 * a double loop. After finding the call for this 2125 * trace_array, we use break to jump to the next 2126 * trace_array. 2127 */ 2128 break; 2129 } while_for_each_event_file(); 2130 } 2131 2132 static void event_remove(struct trace_event_call *call) 2133 { 2134 struct trace_array *tr; 2135 struct trace_event_file *file; 2136 2137 do_for_each_event_file(tr, file) { 2138 if (file->event_call != call) 2139 continue; 2140 ftrace_event_enable_disable(file, 0); 2141 /* 2142 * The do_for_each_event_file() is 2143 * a double loop. After finding the call for this 2144 * trace_array, we use break to jump to the next 2145 * trace_array. 2146 */ 2147 break; 2148 } while_for_each_event_file(); 2149 2150 if (call->event.funcs) 2151 __unregister_trace_event(&call->event); 2152 remove_event_from_tracers(call); 2153 list_del(&call->list); 2154 } 2155 2156 static int event_init(struct trace_event_call *call) 2157 { 2158 int ret = 0; 2159 const char *name; 2160 2161 name = trace_event_name(call); 2162 if (WARN_ON(!name)) 2163 return -EINVAL; 2164 2165 if (call->class->raw_init) { 2166 ret = call->class->raw_init(call); 2167 if (ret < 0 && ret != -ENOSYS) 2168 pr_warn("Could not initialize trace events/%s\n", name); 2169 } 2170 2171 return ret; 2172 } 2173 2174 static int 2175 __register_event(struct trace_event_call *call, struct module *mod) 2176 { 2177 int ret; 2178 2179 ret = event_init(call); 2180 if (ret < 0) 2181 return ret; 2182 2183 list_add(&call->list, &ftrace_events); 2184 call->mod = mod; 2185 2186 return 0; 2187 } 2188 2189 static char *enum_replace(char *ptr, struct trace_enum_map *map, int len) 2190 { 2191 int rlen; 2192 int elen; 2193 2194 /* Find the length of the enum value as a string */ 2195 elen = snprintf(ptr, 0, "%ld", map->enum_value); 2196 /* Make sure there's enough room to replace the string with the value */ 2197 if (len < elen) 2198 return NULL; 2199 2200 snprintf(ptr, elen + 1, "%ld", map->enum_value); 2201 2202 /* Get the rest of the string of ptr */ 2203 rlen = strlen(ptr + len); 2204 memmove(ptr + elen, ptr + len, rlen); 2205 /* Make sure we end the new string */ 2206 ptr[elen + rlen] = 0; 2207 2208 return ptr + elen; 2209 } 2210 2211 static void update_event_printk(struct trace_event_call *call, 2212 struct trace_enum_map *map) 2213 { 2214 char *ptr; 2215 int quote = 0; 2216 int len = strlen(map->enum_string); 2217 2218 for (ptr = call->print_fmt; *ptr; ptr++) { 2219 if (*ptr == '\\') { 2220 ptr++; 2221 /* paranoid */ 2222 if (!*ptr) 2223 break; 2224 continue; 2225 } 2226 if (*ptr == '"') { 2227 quote ^= 1; 2228 continue; 2229 } 2230 if (quote) 2231 continue; 2232 if (isdigit(*ptr)) { 2233 /* skip numbers */ 2234 do { 2235 ptr++; 2236 /* Check for alpha chars like ULL */ 2237 } while (isalnum(*ptr)); 2238 if (!*ptr) 2239 break; 2240 /* 2241 * A number must have some kind of delimiter after 2242 * it, and we can ignore that too. 2243 */ 2244 continue; 2245 } 2246 if (isalpha(*ptr) || *ptr == '_') { 2247 if (strncmp(map->enum_string, ptr, len) == 0 && 2248 !isalnum(ptr[len]) && ptr[len] != '_') { 2249 ptr = enum_replace(ptr, map, len); 2250 /* Hmm, enum string smaller than value */ 2251 if (WARN_ON_ONCE(!ptr)) 2252 return; 2253 /* 2254 * No need to decrement here, as enum_replace() 2255 * returns the pointer to the character passed 2256 * the enum, and two enums can not be placed 2257 * back to back without something in between. 2258 * We can skip that something in between. 2259 */ 2260 continue; 2261 } 2262 skip_more: 2263 do { 2264 ptr++; 2265 } while (isalnum(*ptr) || *ptr == '_'); 2266 if (!*ptr) 2267 break; 2268 /* 2269 * If what comes after this variable is a '.' or 2270 * '->' then we can continue to ignore that string. 2271 */ 2272 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) { 2273 ptr += *ptr == '.' ? 1 : 2; 2274 if (!*ptr) 2275 break; 2276 goto skip_more; 2277 } 2278 /* 2279 * Once again, we can skip the delimiter that came 2280 * after the string. 2281 */ 2282 continue; 2283 } 2284 } 2285 } 2286 2287 void trace_event_enum_update(struct trace_enum_map **map, int len) 2288 { 2289 struct trace_event_call *call, *p; 2290 const char *last_system = NULL; 2291 int last_i; 2292 int i; 2293 2294 down_write(&trace_event_sem); 2295 list_for_each_entry_safe(call, p, &ftrace_events, list) { 2296 /* events are usually grouped together with systems */ 2297 if (!last_system || call->class->system != last_system) { 2298 last_i = 0; 2299 last_system = call->class->system; 2300 } 2301 2302 for (i = last_i; i < len; i++) { 2303 if (call->class->system == map[i]->system) { 2304 /* Save the first system if need be */ 2305 if (!last_i) 2306 last_i = i; 2307 update_event_printk(call, map[i]); 2308 } 2309 } 2310 } 2311 up_write(&trace_event_sem); 2312 } 2313 2314 static struct trace_event_file * 2315 trace_create_new_event(struct trace_event_call *call, 2316 struct trace_array *tr) 2317 { 2318 struct trace_event_file *file; 2319 2320 file = kmem_cache_alloc(file_cachep, GFP_TRACE); 2321 if (!file) 2322 return NULL; 2323 2324 file->event_call = call; 2325 file->tr = tr; 2326 atomic_set(&file->sm_ref, 0); 2327 atomic_set(&file->tm_ref, 0); 2328 INIT_LIST_HEAD(&file->triggers); 2329 list_add(&file->list, &tr->events); 2330 2331 return file; 2332 } 2333 2334 /* Add an event to a trace directory */ 2335 static int 2336 __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr) 2337 { 2338 struct trace_event_file *file; 2339 2340 file = trace_create_new_event(call, tr); 2341 if (!file) 2342 return -ENOMEM; 2343 2344 return event_create_dir(tr->event_dir, file); 2345 } 2346 2347 /* 2348 * Just create a decriptor for early init. A descriptor is required 2349 * for enabling events at boot. We want to enable events before 2350 * the filesystem is initialized. 2351 */ 2352 static __init int 2353 __trace_early_add_new_event(struct trace_event_call *call, 2354 struct trace_array *tr) 2355 { 2356 struct trace_event_file *file; 2357 2358 file = trace_create_new_event(call, tr); 2359 if (!file) 2360 return -ENOMEM; 2361 2362 return 0; 2363 } 2364 2365 struct ftrace_module_file_ops; 2366 static void __add_event_to_tracers(struct trace_event_call *call); 2367 2368 /* Add an additional event_call dynamically */ 2369 int trace_add_event_call(struct trace_event_call *call) 2370 { 2371 int ret; 2372 mutex_lock(&trace_types_lock); 2373 mutex_lock(&event_mutex); 2374 2375 ret = __register_event(call, NULL); 2376 if (ret >= 0) 2377 __add_event_to_tracers(call); 2378 2379 mutex_unlock(&event_mutex); 2380 mutex_unlock(&trace_types_lock); 2381 return ret; 2382 } 2383 2384 /* 2385 * Must be called under locking of trace_types_lock, event_mutex and 2386 * trace_event_sem. 2387 */ 2388 static void __trace_remove_event_call(struct trace_event_call *call) 2389 { 2390 event_remove(call); 2391 trace_destroy_fields(call); 2392 free_event_filter(call->filter); 2393 call->filter = NULL; 2394 } 2395 2396 static int probe_remove_event_call(struct trace_event_call *call) 2397 { 2398 struct trace_array *tr; 2399 struct trace_event_file *file; 2400 2401 #ifdef CONFIG_PERF_EVENTS 2402 if (call->perf_refcount) 2403 return -EBUSY; 2404 #endif 2405 do_for_each_event_file(tr, file) { 2406 if (file->event_call != call) 2407 continue; 2408 /* 2409 * We can't rely on ftrace_event_enable_disable(enable => 0) 2410 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress 2411 * TRACE_REG_UNREGISTER. 2412 */ 2413 if (file->flags & EVENT_FILE_FL_ENABLED) 2414 return -EBUSY; 2415 /* 2416 * The do_for_each_event_file_safe() is 2417 * a double loop. After finding the call for this 2418 * trace_array, we use break to jump to the next 2419 * trace_array. 2420 */ 2421 break; 2422 } while_for_each_event_file(); 2423 2424 __trace_remove_event_call(call); 2425 2426 return 0; 2427 } 2428 2429 /* Remove an event_call */ 2430 int trace_remove_event_call(struct trace_event_call *call) 2431 { 2432 int ret; 2433 2434 mutex_lock(&trace_types_lock); 2435 mutex_lock(&event_mutex); 2436 down_write(&trace_event_sem); 2437 ret = probe_remove_event_call(call); 2438 up_write(&trace_event_sem); 2439 mutex_unlock(&event_mutex); 2440 mutex_unlock(&trace_types_lock); 2441 2442 return ret; 2443 } 2444 2445 #define for_each_event(event, start, end) \ 2446 for (event = start; \ 2447 (unsigned long)event < (unsigned long)end; \ 2448 event++) 2449 2450 #ifdef CONFIG_MODULES 2451 2452 static void trace_module_add_events(struct module *mod) 2453 { 2454 struct trace_event_call **call, **start, **end; 2455 2456 if (!mod->num_trace_events) 2457 return; 2458 2459 /* Don't add infrastructure for mods without tracepoints */ 2460 if (trace_module_has_bad_taint(mod)) { 2461 pr_err("%s: module has bad taint, not creating trace events\n", 2462 mod->name); 2463 return; 2464 } 2465 2466 start = mod->trace_events; 2467 end = mod->trace_events + mod->num_trace_events; 2468 2469 for_each_event(call, start, end) { 2470 __register_event(*call, mod); 2471 __add_event_to_tracers(*call); 2472 } 2473 } 2474 2475 static void trace_module_remove_events(struct module *mod) 2476 { 2477 struct trace_event_call *call, *p; 2478 bool clear_trace = false; 2479 2480 down_write(&trace_event_sem); 2481 list_for_each_entry_safe(call, p, &ftrace_events, list) { 2482 if (call->mod == mod) { 2483 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED) 2484 clear_trace = true; 2485 __trace_remove_event_call(call); 2486 } 2487 } 2488 up_write(&trace_event_sem); 2489 2490 /* 2491 * It is safest to reset the ring buffer if the module being unloaded 2492 * registered any events that were used. The only worry is if 2493 * a new module gets loaded, and takes on the same id as the events 2494 * of this module. When printing out the buffer, traced events left 2495 * over from this module may be passed to the new module events and 2496 * unexpected results may occur. 2497 */ 2498 if (clear_trace) 2499 tracing_reset_all_online_cpus(); 2500 } 2501 2502 static int trace_module_notify(struct notifier_block *self, 2503 unsigned long val, void *data) 2504 { 2505 struct module *mod = data; 2506 2507 mutex_lock(&trace_types_lock); 2508 mutex_lock(&event_mutex); 2509 switch (val) { 2510 case MODULE_STATE_COMING: 2511 trace_module_add_events(mod); 2512 break; 2513 case MODULE_STATE_GOING: 2514 trace_module_remove_events(mod); 2515 break; 2516 } 2517 mutex_unlock(&event_mutex); 2518 mutex_unlock(&trace_types_lock); 2519 2520 return 0; 2521 } 2522 2523 static struct notifier_block trace_module_nb = { 2524 .notifier_call = trace_module_notify, 2525 .priority = 1, /* higher than trace.c module notify */ 2526 }; 2527 #endif /* CONFIG_MODULES */ 2528 2529 /* Create a new event directory structure for a trace directory. */ 2530 static void 2531 __trace_add_event_dirs(struct trace_array *tr) 2532 { 2533 struct trace_event_call *call; 2534 int ret; 2535 2536 list_for_each_entry(call, &ftrace_events, list) { 2537 ret = __trace_add_new_event(call, tr); 2538 if (ret < 0) 2539 pr_warn("Could not create directory for event %s\n", 2540 trace_event_name(call)); 2541 } 2542 } 2543 2544 struct trace_event_file * 2545 find_event_file(struct trace_array *tr, const char *system, const char *event) 2546 { 2547 struct trace_event_file *file; 2548 struct trace_event_call *call; 2549 const char *name; 2550 2551 list_for_each_entry(file, &tr->events, list) { 2552 2553 call = file->event_call; 2554 name = trace_event_name(call); 2555 2556 if (!name || !call->class || !call->class->reg) 2557 continue; 2558 2559 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) 2560 continue; 2561 2562 if (strcmp(event, name) == 0 && 2563 strcmp(system, call->class->system) == 0) 2564 return file; 2565 } 2566 return NULL; 2567 } 2568 2569 #ifdef CONFIG_DYNAMIC_FTRACE 2570 2571 /* Avoid typos */ 2572 #define ENABLE_EVENT_STR "enable_event" 2573 #define DISABLE_EVENT_STR "disable_event" 2574 2575 struct event_probe_data { 2576 struct trace_event_file *file; 2577 unsigned long count; 2578 int ref; 2579 bool enable; 2580 }; 2581 2582 static void 2583 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data) 2584 { 2585 struct event_probe_data **pdata = (struct event_probe_data **)_data; 2586 struct event_probe_data *data = *pdata; 2587 2588 if (!data) 2589 return; 2590 2591 if (data->enable) 2592 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags); 2593 else 2594 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags); 2595 } 2596 2597 static void 2598 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data) 2599 { 2600 struct event_probe_data **pdata = (struct event_probe_data **)_data; 2601 struct event_probe_data *data = *pdata; 2602 2603 if (!data) 2604 return; 2605 2606 if (!data->count) 2607 return; 2608 2609 /* Skip if the event is in a state we want to switch to */ 2610 if (data->enable == !(data->file->flags & EVENT_FILE_FL_SOFT_DISABLED)) 2611 return; 2612 2613 if (data->count != -1) 2614 (data->count)--; 2615 2616 event_enable_probe(ip, parent_ip, _data); 2617 } 2618 2619 static int 2620 event_enable_print(struct seq_file *m, unsigned long ip, 2621 struct ftrace_probe_ops *ops, void *_data) 2622 { 2623 struct event_probe_data *data = _data; 2624 2625 seq_printf(m, "%ps:", (void *)ip); 2626 2627 seq_printf(m, "%s:%s:%s", 2628 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR, 2629 data->file->event_call->class->system, 2630 trace_event_name(data->file->event_call)); 2631 2632 if (data->count == -1) 2633 seq_puts(m, ":unlimited\n"); 2634 else 2635 seq_printf(m, ":count=%ld\n", data->count); 2636 2637 return 0; 2638 } 2639 2640 static int 2641 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip, 2642 void **_data) 2643 { 2644 struct event_probe_data **pdata = (struct event_probe_data **)_data; 2645 struct event_probe_data *data = *pdata; 2646 2647 data->ref++; 2648 return 0; 2649 } 2650 2651 static void 2652 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip, 2653 void **_data) 2654 { 2655 struct event_probe_data **pdata = (struct event_probe_data **)_data; 2656 struct event_probe_data *data = *pdata; 2657 2658 if (WARN_ON_ONCE(data->ref <= 0)) 2659 return; 2660 2661 data->ref--; 2662 if (!data->ref) { 2663 /* Remove the SOFT_MODE flag */ 2664 __ftrace_event_enable_disable(data->file, 0, 1); 2665 module_put(data->file->event_call->mod); 2666 kfree(data); 2667 } 2668 *pdata = NULL; 2669 } 2670 2671 static struct ftrace_probe_ops event_enable_probe_ops = { 2672 .func = event_enable_probe, 2673 .print = event_enable_print, 2674 .init = event_enable_init, 2675 .free = event_enable_free, 2676 }; 2677 2678 static struct ftrace_probe_ops event_enable_count_probe_ops = { 2679 .func = event_enable_count_probe, 2680 .print = event_enable_print, 2681 .init = event_enable_init, 2682 .free = event_enable_free, 2683 }; 2684 2685 static struct ftrace_probe_ops event_disable_probe_ops = { 2686 .func = event_enable_probe, 2687 .print = event_enable_print, 2688 .init = event_enable_init, 2689 .free = event_enable_free, 2690 }; 2691 2692 static struct ftrace_probe_ops event_disable_count_probe_ops = { 2693 .func = event_enable_count_probe, 2694 .print = event_enable_print, 2695 .init = event_enable_init, 2696 .free = event_enable_free, 2697 }; 2698 2699 static int 2700 event_enable_func(struct ftrace_hash *hash, 2701 char *glob, char *cmd, char *param, int enabled) 2702 { 2703 struct trace_array *tr = top_trace_array(); 2704 struct trace_event_file *file; 2705 struct ftrace_probe_ops *ops; 2706 struct event_probe_data *data; 2707 const char *system; 2708 const char *event; 2709 char *number; 2710 bool enable; 2711 int ret; 2712 2713 if (!tr) 2714 return -ENODEV; 2715 2716 /* hash funcs only work with set_ftrace_filter */ 2717 if (!enabled || !param) 2718 return -EINVAL; 2719 2720 system = strsep(¶m, ":"); 2721 if (!param) 2722 return -EINVAL; 2723 2724 event = strsep(¶m, ":"); 2725 2726 mutex_lock(&event_mutex); 2727 2728 ret = -EINVAL; 2729 file = find_event_file(tr, system, event); 2730 if (!file) 2731 goto out; 2732 2733 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; 2734 2735 if (enable) 2736 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops; 2737 else 2738 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops; 2739 2740 if (glob[0] == '!') { 2741 unregister_ftrace_function_probe_func(glob+1, ops); 2742 ret = 0; 2743 goto out; 2744 } 2745 2746 ret = -ENOMEM; 2747 data = kzalloc(sizeof(*data), GFP_KERNEL); 2748 if (!data) 2749 goto out; 2750 2751 data->enable = enable; 2752 data->count = -1; 2753 data->file = file; 2754 2755 if (!param) 2756 goto out_reg; 2757 2758 number = strsep(¶m, ":"); 2759 2760 ret = -EINVAL; 2761 if (!strlen(number)) 2762 goto out_free; 2763 2764 /* 2765 * We use the callback data field (which is a pointer) 2766 * as our counter. 2767 */ 2768 ret = kstrtoul(number, 0, &data->count); 2769 if (ret) 2770 goto out_free; 2771 2772 out_reg: 2773 /* Don't let event modules unload while probe registered */ 2774 ret = try_module_get(file->event_call->mod); 2775 if (!ret) { 2776 ret = -EBUSY; 2777 goto out_free; 2778 } 2779 2780 ret = __ftrace_event_enable_disable(file, 1, 1); 2781 if (ret < 0) 2782 goto out_put; 2783 ret = register_ftrace_function_probe(glob, ops, data); 2784 /* 2785 * The above returns on success the # of functions enabled, 2786 * but if it didn't find any functions it returns zero. 2787 * Consider no functions a failure too. 2788 */ 2789 if (!ret) { 2790 ret = -ENOENT; 2791 goto out_disable; 2792 } else if (ret < 0) 2793 goto out_disable; 2794 /* Just return zero, not the number of enabled functions */ 2795 ret = 0; 2796 out: 2797 mutex_unlock(&event_mutex); 2798 return ret; 2799 2800 out_disable: 2801 __ftrace_event_enable_disable(file, 0, 1); 2802 out_put: 2803 module_put(file->event_call->mod); 2804 out_free: 2805 kfree(data); 2806 goto out; 2807 } 2808 2809 static struct ftrace_func_command event_enable_cmd = { 2810 .name = ENABLE_EVENT_STR, 2811 .func = event_enable_func, 2812 }; 2813 2814 static struct ftrace_func_command event_disable_cmd = { 2815 .name = DISABLE_EVENT_STR, 2816 .func = event_enable_func, 2817 }; 2818 2819 static __init int register_event_cmds(void) 2820 { 2821 int ret; 2822 2823 ret = register_ftrace_command(&event_enable_cmd); 2824 if (WARN_ON(ret < 0)) 2825 return ret; 2826 ret = register_ftrace_command(&event_disable_cmd); 2827 if (WARN_ON(ret < 0)) 2828 unregister_ftrace_command(&event_enable_cmd); 2829 return ret; 2830 } 2831 #else 2832 static inline int register_event_cmds(void) { return 0; } 2833 #endif /* CONFIG_DYNAMIC_FTRACE */ 2834 2835 /* 2836 * The top level array has already had its trace_event_file 2837 * descriptors created in order to allow for early events to 2838 * be recorded. This function is called after the tracefs has been 2839 * initialized, and we now have to create the files associated 2840 * to the events. 2841 */ 2842 static __init void 2843 __trace_early_add_event_dirs(struct trace_array *tr) 2844 { 2845 struct trace_event_file *file; 2846 int ret; 2847 2848 2849 list_for_each_entry(file, &tr->events, list) { 2850 ret = event_create_dir(tr->event_dir, file); 2851 if (ret < 0) 2852 pr_warn("Could not create directory for event %s\n", 2853 trace_event_name(file->event_call)); 2854 } 2855 } 2856 2857 /* 2858 * For early boot up, the top trace array requires to have 2859 * a list of events that can be enabled. This must be done before 2860 * the filesystem is set up in order to allow events to be traced 2861 * early. 2862 */ 2863 static __init void 2864 __trace_early_add_events(struct trace_array *tr) 2865 { 2866 struct trace_event_call *call; 2867 int ret; 2868 2869 list_for_each_entry(call, &ftrace_events, list) { 2870 /* Early boot up should not have any modules loaded */ 2871 if (WARN_ON_ONCE(call->mod)) 2872 continue; 2873 2874 ret = __trace_early_add_new_event(call, tr); 2875 if (ret < 0) 2876 pr_warn("Could not create early event %s\n", 2877 trace_event_name(call)); 2878 } 2879 } 2880 2881 /* Remove the event directory structure for a trace directory. */ 2882 static void 2883 __trace_remove_event_dirs(struct trace_array *tr) 2884 { 2885 struct trace_event_file *file, *next; 2886 2887 list_for_each_entry_safe(file, next, &tr->events, list) 2888 remove_event_file_dir(file); 2889 } 2890 2891 static void __add_event_to_tracers(struct trace_event_call *call) 2892 { 2893 struct trace_array *tr; 2894 2895 list_for_each_entry(tr, &ftrace_trace_arrays, list) 2896 __trace_add_new_event(call, tr); 2897 } 2898 2899 extern struct trace_event_call *__start_ftrace_events[]; 2900 extern struct trace_event_call *__stop_ftrace_events[]; 2901 2902 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata; 2903 2904 static __init int setup_trace_event(char *str) 2905 { 2906 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE); 2907 ring_buffer_expanded = true; 2908 tracing_selftest_disabled = true; 2909 2910 return 1; 2911 } 2912 __setup("trace_event=", setup_trace_event); 2913 2914 /* Expects to have event_mutex held when called */ 2915 static int 2916 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr) 2917 { 2918 struct dentry *d_events; 2919 struct dentry *entry; 2920 2921 entry = tracefs_create_file("set_event", 0644, parent, 2922 tr, &ftrace_set_event_fops); 2923 if (!entry) { 2924 pr_warn("Could not create tracefs 'set_event' entry\n"); 2925 return -ENOMEM; 2926 } 2927 2928 d_events = tracefs_create_dir("events", parent); 2929 if (!d_events) { 2930 pr_warn("Could not create tracefs 'events' directory\n"); 2931 return -ENOMEM; 2932 } 2933 2934 entry = tracefs_create_file("set_event_pid", 0644, parent, 2935 tr, &ftrace_set_event_pid_fops); 2936 2937 /* ring buffer internal formats */ 2938 trace_create_file("header_page", 0444, d_events, 2939 ring_buffer_print_page_header, 2940 &ftrace_show_header_fops); 2941 2942 trace_create_file("header_event", 0444, d_events, 2943 ring_buffer_print_entry_header, 2944 &ftrace_show_header_fops); 2945 2946 trace_create_file("enable", 0644, d_events, 2947 tr, &ftrace_tr_enable_fops); 2948 2949 tr->event_dir = d_events; 2950 2951 return 0; 2952 } 2953 2954 /** 2955 * event_trace_add_tracer - add a instance of a trace_array to events 2956 * @parent: The parent dentry to place the files/directories for events in 2957 * @tr: The trace array associated with these events 2958 * 2959 * When a new instance is created, it needs to set up its events 2960 * directory, as well as other files associated with events. It also 2961 * creates the event hierachry in the @parent/events directory. 2962 * 2963 * Returns 0 on success. 2964 */ 2965 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr) 2966 { 2967 int ret; 2968 2969 mutex_lock(&event_mutex); 2970 2971 ret = create_event_toplevel_files(parent, tr); 2972 if (ret) 2973 goto out_unlock; 2974 2975 down_write(&trace_event_sem); 2976 __trace_add_event_dirs(tr); 2977 up_write(&trace_event_sem); 2978 2979 out_unlock: 2980 mutex_unlock(&event_mutex); 2981 2982 return ret; 2983 } 2984 2985 /* 2986 * The top trace array already had its file descriptors created. 2987 * Now the files themselves need to be created. 2988 */ 2989 static __init int 2990 early_event_add_tracer(struct dentry *parent, struct trace_array *tr) 2991 { 2992 int ret; 2993 2994 mutex_lock(&event_mutex); 2995 2996 ret = create_event_toplevel_files(parent, tr); 2997 if (ret) 2998 goto out_unlock; 2999 3000 down_write(&trace_event_sem); 3001 __trace_early_add_event_dirs(tr); 3002 up_write(&trace_event_sem); 3003 3004 out_unlock: 3005 mutex_unlock(&event_mutex); 3006 3007 return ret; 3008 } 3009 3010 int event_trace_del_tracer(struct trace_array *tr) 3011 { 3012 mutex_lock(&event_mutex); 3013 3014 /* Disable any event triggers and associated soft-disabled events */ 3015 clear_event_triggers(tr); 3016 3017 /* Clear the pid list */ 3018 __ftrace_clear_event_pids(tr); 3019 3020 /* Disable any running events */ 3021 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0); 3022 3023 /* Access to events are within rcu_read_lock_sched() */ 3024 synchronize_sched(); 3025 3026 down_write(&trace_event_sem); 3027 __trace_remove_event_dirs(tr); 3028 tracefs_remove_recursive(tr->event_dir); 3029 up_write(&trace_event_sem); 3030 3031 tr->event_dir = NULL; 3032 3033 mutex_unlock(&event_mutex); 3034 3035 return 0; 3036 } 3037 3038 static __init int event_trace_memsetup(void) 3039 { 3040 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC); 3041 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC); 3042 return 0; 3043 } 3044 3045 static __init void 3046 early_enable_events(struct trace_array *tr, bool disable_first) 3047 { 3048 char *buf = bootup_event_buf; 3049 char *token; 3050 int ret; 3051 3052 while (true) { 3053 token = strsep(&buf, ","); 3054 3055 if (!token) 3056 break; 3057 3058 if (*token) { 3059 /* Restarting syscalls requires that we stop them first */ 3060 if (disable_first) 3061 ftrace_set_clr_event(tr, token, 0); 3062 3063 ret = ftrace_set_clr_event(tr, token, 1); 3064 if (ret) 3065 pr_warn("Failed to enable trace event: %s\n", token); 3066 } 3067 3068 /* Put back the comma to allow this to be called again */ 3069 if (buf) 3070 *(buf - 1) = ','; 3071 } 3072 } 3073 3074 static __init int event_trace_enable(void) 3075 { 3076 struct trace_array *tr = top_trace_array(); 3077 struct trace_event_call **iter, *call; 3078 int ret; 3079 3080 if (!tr) 3081 return -ENODEV; 3082 3083 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) { 3084 3085 call = *iter; 3086 ret = event_init(call); 3087 if (!ret) 3088 list_add(&call->list, &ftrace_events); 3089 } 3090 3091 /* 3092 * We need the top trace array to have a working set of trace 3093 * points at early init, before the debug files and directories 3094 * are created. Create the file entries now, and attach them 3095 * to the actual file dentries later. 3096 */ 3097 __trace_early_add_events(tr); 3098 3099 early_enable_events(tr, false); 3100 3101 trace_printk_start_comm(); 3102 3103 register_event_cmds(); 3104 3105 register_trigger_cmds(); 3106 3107 return 0; 3108 } 3109 3110 /* 3111 * event_trace_enable() is called from trace_event_init() first to 3112 * initialize events and perhaps start any events that are on the 3113 * command line. Unfortunately, there are some events that will not 3114 * start this early, like the system call tracepoints that need 3115 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable() 3116 * is called before pid 1 starts, and this flag is never set, making 3117 * the syscall tracepoint never get reached, but the event is enabled 3118 * regardless (and not doing anything). 3119 */ 3120 static __init int event_trace_enable_again(void) 3121 { 3122 struct trace_array *tr; 3123 3124 tr = top_trace_array(); 3125 if (!tr) 3126 return -ENODEV; 3127 3128 early_enable_events(tr, true); 3129 3130 return 0; 3131 } 3132 3133 early_initcall(event_trace_enable_again); 3134 3135 static __init int event_trace_init(void) 3136 { 3137 struct trace_array *tr; 3138 struct dentry *d_tracer; 3139 struct dentry *entry; 3140 int ret; 3141 3142 tr = top_trace_array(); 3143 if (!tr) 3144 return -ENODEV; 3145 3146 d_tracer = tracing_init_dentry(); 3147 if (IS_ERR(d_tracer)) 3148 return 0; 3149 3150 entry = tracefs_create_file("available_events", 0444, d_tracer, 3151 tr, &ftrace_avail_fops); 3152 if (!entry) 3153 pr_warn("Could not create tracefs 'available_events' entry\n"); 3154 3155 if (trace_define_generic_fields()) 3156 pr_warn("tracing: Failed to allocated generic fields"); 3157 3158 if (trace_define_common_fields()) 3159 pr_warn("tracing: Failed to allocate common fields"); 3160 3161 ret = early_event_add_tracer(d_tracer, tr); 3162 if (ret) 3163 return ret; 3164 3165 #ifdef CONFIG_MODULES 3166 ret = register_module_notifier(&trace_module_nb); 3167 if (ret) 3168 pr_warn("Failed to register trace events module notifier\n"); 3169 #endif 3170 return 0; 3171 } 3172 3173 void __init trace_event_init(void) 3174 { 3175 event_trace_memsetup(); 3176 init_ftrace_syscalls(); 3177 event_trace_enable(); 3178 } 3179 3180 fs_initcall(event_trace_init); 3181 3182 #ifdef CONFIG_FTRACE_STARTUP_TEST 3183 3184 static DEFINE_SPINLOCK(test_spinlock); 3185 static DEFINE_SPINLOCK(test_spinlock_irq); 3186 static DEFINE_MUTEX(test_mutex); 3187 3188 static __init void test_work(struct work_struct *dummy) 3189 { 3190 spin_lock(&test_spinlock); 3191 spin_lock_irq(&test_spinlock_irq); 3192 udelay(1); 3193 spin_unlock_irq(&test_spinlock_irq); 3194 spin_unlock(&test_spinlock); 3195 3196 mutex_lock(&test_mutex); 3197 msleep(1); 3198 mutex_unlock(&test_mutex); 3199 } 3200 3201 static __init int event_test_thread(void *unused) 3202 { 3203 void *test_malloc; 3204 3205 test_malloc = kmalloc(1234, GFP_KERNEL); 3206 if (!test_malloc) 3207 pr_info("failed to kmalloc\n"); 3208 3209 schedule_on_each_cpu(test_work); 3210 3211 kfree(test_malloc); 3212 3213 set_current_state(TASK_INTERRUPTIBLE); 3214 while (!kthread_should_stop()) { 3215 schedule(); 3216 set_current_state(TASK_INTERRUPTIBLE); 3217 } 3218 __set_current_state(TASK_RUNNING); 3219 3220 return 0; 3221 } 3222 3223 /* 3224 * Do various things that may trigger events. 3225 */ 3226 static __init void event_test_stuff(void) 3227 { 3228 struct task_struct *test_thread; 3229 3230 test_thread = kthread_run(event_test_thread, NULL, "test-events"); 3231 msleep(1); 3232 kthread_stop(test_thread); 3233 } 3234 3235 /* 3236 * For every trace event defined, we will test each trace point separately, 3237 * and then by groups, and finally all trace points. 3238 */ 3239 static __init void event_trace_self_tests(void) 3240 { 3241 struct trace_subsystem_dir *dir; 3242 struct trace_event_file *file; 3243 struct trace_event_call *call; 3244 struct event_subsystem *system; 3245 struct trace_array *tr; 3246 int ret; 3247 3248 tr = top_trace_array(); 3249 if (!tr) 3250 return; 3251 3252 pr_info("Running tests on trace events:\n"); 3253 3254 list_for_each_entry(file, &tr->events, list) { 3255 3256 call = file->event_call; 3257 3258 /* Only test those that have a probe */ 3259 if (!call->class || !call->class->probe) 3260 continue; 3261 3262 /* 3263 * Testing syscall events here is pretty useless, but 3264 * we still do it if configured. But this is time consuming. 3265 * What we really need is a user thread to perform the 3266 * syscalls as we test. 3267 */ 3268 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS 3269 if (call->class->system && 3270 strcmp(call->class->system, "syscalls") == 0) 3271 continue; 3272 #endif 3273 3274 pr_info("Testing event %s: ", trace_event_name(call)); 3275 3276 /* 3277 * If an event is already enabled, someone is using 3278 * it and the self test should not be on. 3279 */ 3280 if (file->flags & EVENT_FILE_FL_ENABLED) { 3281 pr_warn("Enabled event during self test!\n"); 3282 WARN_ON_ONCE(1); 3283 continue; 3284 } 3285 3286 ftrace_event_enable_disable(file, 1); 3287 event_test_stuff(); 3288 ftrace_event_enable_disable(file, 0); 3289 3290 pr_cont("OK\n"); 3291 } 3292 3293 /* Now test at the sub system level */ 3294 3295 pr_info("Running tests on trace event systems:\n"); 3296 3297 list_for_each_entry(dir, &tr->systems, list) { 3298 3299 system = dir->subsystem; 3300 3301 /* the ftrace system is special, skip it */ 3302 if (strcmp(system->name, "ftrace") == 0) 3303 continue; 3304 3305 pr_info("Testing event system %s: ", system->name); 3306 3307 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1); 3308 if (WARN_ON_ONCE(ret)) { 3309 pr_warn("error enabling system %s\n", 3310 system->name); 3311 continue; 3312 } 3313 3314 event_test_stuff(); 3315 3316 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0); 3317 if (WARN_ON_ONCE(ret)) { 3318 pr_warn("error disabling system %s\n", 3319 system->name); 3320 continue; 3321 } 3322 3323 pr_cont("OK\n"); 3324 } 3325 3326 /* Test with all events enabled */ 3327 3328 pr_info("Running tests on all trace events:\n"); 3329 pr_info("Testing all events: "); 3330 3331 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1); 3332 if (WARN_ON_ONCE(ret)) { 3333 pr_warn("error enabling all events\n"); 3334 return; 3335 } 3336 3337 event_test_stuff(); 3338 3339 /* reset sysname */ 3340 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0); 3341 if (WARN_ON_ONCE(ret)) { 3342 pr_warn("error disabling all events\n"); 3343 return; 3344 } 3345 3346 pr_cont("OK\n"); 3347 } 3348 3349 #ifdef CONFIG_FUNCTION_TRACER 3350 3351 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable); 3352 3353 static struct trace_array *event_tr; 3354 3355 static void __init 3356 function_test_events_call(unsigned long ip, unsigned long parent_ip, 3357 struct ftrace_ops *op, struct pt_regs *pt_regs) 3358 { 3359 struct ring_buffer_event *event; 3360 struct ring_buffer *buffer; 3361 struct ftrace_entry *entry; 3362 unsigned long flags; 3363 long disabled; 3364 int cpu; 3365 int pc; 3366 3367 pc = preempt_count(); 3368 preempt_disable_notrace(); 3369 cpu = raw_smp_processor_id(); 3370 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu)); 3371 3372 if (disabled != 1) 3373 goto out; 3374 3375 local_save_flags(flags); 3376 3377 event = trace_current_buffer_lock_reserve(&buffer, 3378 TRACE_FN, sizeof(*entry), 3379 flags, pc); 3380 if (!event) 3381 goto out; 3382 entry = ring_buffer_event_data(event); 3383 entry->ip = ip; 3384 entry->parent_ip = parent_ip; 3385 3386 trace_buffer_unlock_commit(event_tr, buffer, event, flags, pc); 3387 3388 out: 3389 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu)); 3390 preempt_enable_notrace(); 3391 } 3392 3393 static struct ftrace_ops trace_ops __initdata = 3394 { 3395 .func = function_test_events_call, 3396 .flags = FTRACE_OPS_FL_RECURSION_SAFE, 3397 }; 3398 3399 static __init void event_trace_self_test_with_function(void) 3400 { 3401 int ret; 3402 event_tr = top_trace_array(); 3403 if (WARN_ON(!event_tr)) 3404 return; 3405 ret = register_ftrace_function(&trace_ops); 3406 if (WARN_ON(ret < 0)) { 3407 pr_info("Failed to enable function tracer for event tests\n"); 3408 return; 3409 } 3410 pr_info("Running tests again, along with the function tracer\n"); 3411 event_trace_self_tests(); 3412 unregister_ftrace_function(&trace_ops); 3413 } 3414 #else 3415 static __init void event_trace_self_test_with_function(void) 3416 { 3417 } 3418 #endif 3419 3420 static __init int event_trace_self_tests_init(void) 3421 { 3422 if (!tracing_selftest_disabled) { 3423 event_trace_self_tests(); 3424 event_trace_self_test_with_function(); 3425 } 3426 3427 return 0; 3428 } 3429 3430 late_initcall(event_trace_self_tests_init); 3431 3432 #endif 3433